Hadro-Production Experiments: Impact on T2K and LBNE

Transcription

1 Hadro-Production Experiments: Impact on T2K and LBNE Alysia Marino University of Colorado Boulder LBNE Scientific Workshop, Santa Fe, NM April 25-26, 24

2 2 Outline T2K Datasets used Flux prediction Flux uncertainties LBNE Currently Available Data Potential future measurements

3 T2K Beam J-PARC Neutrino facility Apparatus inbeam beam-line Horn Installation!!"#$%&&%'(")#*++,,-,-)(").%"/)#$/) Muon Monitor Horn Beam monitors Si array + IC array Super-Conducting Magnets intensity, position profile 3 Horns w/ 25kA to Super-K νμ Near detector μ+!+ 3(%#345#/)26%/ &+>*&5?*<.:/>< DecayVolume Target (at 28m from target)!"#$%&'()*+,"#-.//&+#"#!)2%//) 3GeV MR Beam Dump m length Graphite,-.2'/#789%2#:%/; Φ26 x Helium cooling 9 mm long proton beam 2 3 GeV/c protons on 9.4 cm long graphite target (ρ=.8 g/cc,.9 λ), fixed in place!"#$%&'()** %+,-./)*234*5''(** 6'*72,8**5''( *9.:-*;,< =5 3

4 4 T2K Beam Flux ND and SK are both ~2.5 o off-axis Very different detector technologies so many cross section and detector uncertainties don t cancel Much of this talk will follow T2K Neutrino Flux Prediction, Phys Rev D, 87 2 (23) Fluka 28 was used at time of paper for hadron interactions in target + baffle Most important hadroproduction data sets for T2K are Allaby, Eichten, and NA6 (see next few slides)

5 5 Allaby Data Data release as J. V. Allaby et al., Tech. Rep. 7-2 (CERN, 97). Took data with a 9.2 GeV/c beam on p,be, Al, Cu, and Pb targets Measured p,pbar, K+-, π+- production from 2.5 to 7 mrad and p from 4.5 to 4 GeV/c

6 Eichten Data 334 T. et al., Proton interactions in nuclei 24 Ge V/c T2 COUJMATOR HOOOSCOPE A ~ " ~ ~ ~.' / ~TTI~ED SEC TARGET -I " ~-~-~"~ ~ J 5 f/ 52 Qa Q9 ~FT~ ' ~ - 2 HOOOSC(O~ B MUON u ~ ~ M ~ MA~T DETECTOR ~ 5 Q OMAI~ 5/,,t S]EERING S 5,CI, mllation COUNTER T COUNTER ELESCOI~ C ~ ~ Published in Fig. T.. Layout Eichten of the magnetic al., spectrometer. Nucl. Phys. B 44, 333 (972). 2. EXPERIMENTAL RESULTS Took data with a 24 GeV/c beam on Be, Al, Cu, and Table shows the measured Lorentz invariant one particle distribution functions Pb targets co(p, ) defined by Measured p,pbar, K+-, π+- production from 7 to d2n_ 62 p2dpd~2 27 mrad o a and 6p6~ dpd~2 p from = co(p, ) 4 to 2E 8 GeV/c where 62o/6p6 ~2 is the differential production cross section, o a is the absorption 6

7 7 Eichten and Allaby K + coverage Plot from Scott Johnson, scaled by x f and p t

8 8 SPS Heavy Ion & Neutrino Experiment 2 TPCs inside superconducting magnets 2 TPCs after magnets ToF detectors A new projectile spectator detector is being commissioned Had used a variety of targets and beams

9 9 NA6 Data for T2K Data Year evts (x 6 ) Status 2 cm target 2 cm target full target π ± :Phys. Rev. C84 (2) 3464 K + :Phys. Rev. C85 (22) 352 Λ: Phys. Rev. C89 (24) 2525 Preliminary π ±, K ±, p, K s, Λ To be published soon π ± method: Nucl. Inst. Meth. A7 (23) 99 full target full target End of 24? 2 All data taken with protons at 3 GeV/c

10 NA6 Coverage for T2K K. ABE et al. PHYSICAL REVIEW D 87, 2 (23) (rad) θ π NA6 Coverage Arb. Units (rad) θ π NA6 Coverage 4 2 Arb. Units (rad) θ K NA6 Coverage Arb. Units (GeV/c) p π (GeV/c) p π (GeV/c) p K FIG. 5 (color online). The phase space of pions and kaons contributing to the predicted neutrino flux at SK, and the regions covered by NA6/SHINE measurements. Colors indicate contribution to T2K flux at SK Covers 9% of π and 6% of K + phase space The positive kaon production measurements were performed with a coarser data binning and for a range of the kinematic variables which covers about 6% of the phase space relevant for T2K. Limitations were imposed by the available statistics year) and by the decreased sensitivity of the kaon identification at larger momenta as a consequence of the vanishing K=p and K= production ratios. The maximum kinematic range considered is between.6 and forward production of high energy kaons, which has not been measured yet by the NA6/SHINE experiment. These data are used to reweight the model predictions in these regions. In addition, the differential proton production measurements in these experiments are used to evaluate systematic uncertainties in secondary nucleon production. The pion production data from the BNL-E9 experiment [29] is used to evaluate systematic uncertainties Will increase in future NA6 analyses (later this

11 Reweighting Weights obtained from comparisons of measured differential multiplicities to MC predictions Reweighting also done for overall σ prod Eichten and Allaby Be data are scaled by x f and target material to cover K regions not covered by NA6 Material scaling uses parameterization suggested in Bonesini et al, Eur. Phys. J. C 2, 3 (2). Rescaled NA6 data also used for tertiary interactions (including in Al)

12 Weights to Fluka T2K NEUTRINO FLUX PREDICTION PHYSICAL REVIEW D 87, 2 (23) (mrad) θ π (mrad) θ π Weight Weight (mrad) θ π 2 R Al/Be The different given simulated ratio of the prod p (GeV/c) For interactions π duce or K þ 3 Data:.6.67 mrad bin SHINE data, th (c) NA6 K Weights Fit: 7 mrad bin straightforward Data: 57 mrad bin (a) NA6 π + Weights Fit:.4 57 mrad bin vided is already 2 Data: 7 mrad bin momentum, and 2.4 Fit: 7 mrad bin.2.2 applied to diff 2.2 interactions are The reweigh 2 cleon interactio SHINE data to.6.6 other target mat in interactions w p (GeV/c).4 π 4 6 p (GeV/c) can also be pr T2K NEUTRINO FLUX PREDICTION K PHYSICAL REVIEW D 87, 2 p (GeV/c) neutrons, (23) in wh.6 reaction 6 The fitted parameter values along with the values FIG. reported 6 (color online)..2 The differential production weights (p þ C in [42] are listed in Table XIII. from NA6/SHINE FIG. 7. Examples data of forthe material þ (top), scaling (middle) exponent and fit forused a to calculat - (b) NA6 π Weights.4 K þ few angular bins in the [27] K þ 5 The NA6/SHINE pion production data are scaled (bottom). to. data. for interactions aluminum using the parameters in Table XIII, and the invariance 4 of th.2 The differential.8 resulting weights applied to the production in GCALOR production weight that is applied to a 2. Hadron differential production reweighting The scaling o 3 are shown in Fig. 8. The weights are calculatedgiven for simulated interaction that produces hadrons is the incident nucleon Theratio differential of the production production.6 GCALOR, since the simulation of interactions in the in data reweighting and simulation: is evaluated scaling 2 [4]. Th horn material is done with GEANT3. using the differential multiplicity in.8 Wðp in ;AÞ¼ ½dn dp ð;p the momentum, p, of.4 The reweighting of K þ and K production in the the produced phase particle and its angle,, in;aþš relative data to the incident particle: ½ dn dp ð;p : (4) space not covered by NA6/SHINE is carried in;aþš MC.6 out using the.2 Eichten et 5 al. [27] and Allaby 5 et al. 2[28] kaon production p (GeV/c) For interactions of 3 GeV=c protons on carbon that produce or K þ in the phase space covered by the NA6/ TABLE X data. Since these π data sets only measure the differential p (GeV/c) dn dp ð;p dk production at points that cover a small momentum and in;aþ¼ prod ðp in ;AÞ dp ð;p in;aþ: (3) 2 (mrad) θ K θ (rad) Weight Weight Data/FLUKA + Eichten K W

13 (GeV/c) p inc Flux FIG. 23. Weights Comparisons of prod measurements and the values used in the simula GCALOR), for incident protons (top left) and charged pions (top right), K þ (botto.6 Pion Tuning.6 Pion T Compared to Fluka 28 Tuning weight.4.2 Kaon Tuning Int. Rate Tuning Total Tuning Tuning weight.4.2 Kaon Int. R Total Top plot shows ν μ flux weights Bottom plot shows ν e flux weights Tuning weight (GeV).6 Pion Tuning Kaon Tuning.4 Int. Rate Tuning Total Tuning.2 E ν Tuning weight 2.6 Pion T Kaon.4 Int. R Total (GeV) E ν 2 3

14 4 Pion Uncertainties Uncertainties from NA6 measurements are used Parameters varied according to covariances There are also additional errors due to rescaling for different p. These are evaluated by comparing to BNL E-9 data (protons on Be at 2.3 and 7.5 GeV/c) For region outside of NA6, error comes from comparison to a BMPT fit of NA6

15 5 Kaon Uncertainties Again uncertainties on data values are used, taking in to account correlations Looking at the Al data from Eichten and Allaby gives an uncertainty due to target material scaling Uncertainty on momentum scaling comes from scaling Allaby data to Eichten incident momentum Again a comparison to a BMPT fit is use to evaluate errors outside of data coverage.

16 4 p,n Uncertainties.5 (GeV/c) T p 3 2 Arb. Units x F secondary p,n make up 6%, 5% of flux Comparisons between FLUKA and Eichten/ Allaby proton data used for x f <.9. Discrepancy is the uncertainty. Above x f >.9, a % uncertainty is used FIG. 35 (color online). Distribution of secondary protons and FLUKA hadron interaction model. (GeV/c) T p x F FIG. 36 (color online). Ratio of the secondary proton measurements from Eichten et al. [27] and Allaby et al. [28] and the FLUKA modeling of secondary protons. Each circle is a point from the data sets Data/FLUKA 6

17 Fractional Error Hadron Production..2 Pion Production Kaon Production Secondary Nucleon Production Production Cross Section Fractional Error.3.2. Fractional Error Fractional Error SK ν µ Flux Total Pion Production Kaon Production Secondary Nucleon Production Production Cross Section Uncertainties Flux BE et al. PHYSICAL REVIEW D 87, 2 (2 - E ν (GeV) SK ν e Flux - E ν (GeV) π and K uncertainties are 6% or less below 3 GeV Pion Production Pion Production.2 Largely dominated by nucleon.3 uncertainties Production Cross Section. Total Kaon Production Secondary Nucleon Production Production Cross Section Fractional Error Fractional Error E ν (GeV) Flux SK ν µ e - Total Pion Production Kaon Production Secondary Nucleon Production Production Cross Section SK ν e Flux FIG. 38 (color online). Total Kaon Production Secondary Nucleon Production 5. Summary of the hadron production uncertainties and prospect from future measurements The uncertainty on the SK flux as a function of neutrino.2 energy due to hadronic interaction uncertainties is shown in Fig. 38. The uncertainties at the off-axis near detector E ν Fractional Error Fractional flux error due t With possib produ SHIN statist rewei 7

18 8 Other Sources of Flux Uncertainty Other beam effects were largely handled by tweaking beam MC and reweighting Beam size, position, and angle Off-axis angle Target and horn alignment Horn current and B-field

19 Fractio. Fractio.2. Fractio. Total Flux Uncertainty (GeV) - E ν - (GeV) E ν Fractional Error.3.2. SK ν µ Flux Total Hadronic Interactions Proton Beam, Alignment and Off-axis Angle Horn Current & Field Fractional Error SK ν e SK ν µ Flux Flux Total Hadronic Interactions Proton Beam, Alignment and Off-axis Angle Horn Current & Field Fractional Error - (GeV) E ν - (GeV) E ν Fractional Error.3.2. SK ν Dominated Flux by hadron production e Flux Total Still more improvements to come, but currently Hadronic Interactions Hadronic Interactions.4 Proton Beam, Alignment and Off-axis Angle Proton Beam, Alignment and Off-axis Angle the flux uncertainties are ~-2% in the Horn Current & Field Horn Current & Field.3 oscillation range of interest Fractional Error.5.2 SK ν e FIG. 43 (color online). Total Fractional flux error

20 2 Prospects for Improving T2K Uncertainties 29 Thin target data >5x more statistics Data will cover more phase space (especially for K) Will have p, Λ, and K data 29 Long Target data

21 2 tional collaboration sources needed immediately LBNE Beam 8-2 GeV/c protons LBNE Collaboration Meeting Feb. 4, MW option currently has a graphite target, will likely be fixed in place Near and Far detectors likely will have very different detector technologies

22 22 Datasets for LBNE MIPP: 2 GeV/c protons on a think and thin target. Preliminary NuMI thick target data presented in April 24 (<% errors in most bins) NA49: p+c data at 58 GeV/c Barton et al: data at GeV/c, but disagrees with NA49 by 2% in region of overlap

23 23 NA6 and LBNE Proposal being submitted to DOE to take data with higher energy protons in NA6 that would benefit Fermilab experiments proton (and pion) data at 2 GeV/c on thin Be, C, and Al targets 2 GeV p+c event in NA6 proton (and pion) data at ~6 GeV/c on thin targets

24 (mrad) θ (mrad) θ π + LBNE Phase Space production momentum (GeV/c) (GeV/c) 5 π and K contributions to flux at LBNE far site K + p tot (GeV/c) Regions of phase space that 5 contribute to LBNE flux are well matched to NA6 phase production momentum (GeV/c) space (mrad) θ (mrad) θ 5 5 π - - K p tot production momentum (GeV/c) Tm (8 GeV field) (GeV/c) p (GeV/c) p.6 tot tot Figure : Pion and Kaon contributions to total neutrino flux at LBNE far site hrow is within the assumed errors. The resulting fractional spread of these models on the preicted far detector neutrino fluxes are shown in Figure. The resulting spread on the predicted µ and e flux at the LBNE far detector is less than 6% below GeV. production angle (mrad) 5 π + π Tm (2 GeV field) Κ + Κ - production angle (mrad) Figure 6: Reconstruction acceptance of the NA6 spectrometer for charged pions at the indicated 24 production a production angle (mrad) production angle (mrad) NA6 Acceptance Tm (4 (8 GeV field) production momentum (GeV/c) Figure 6: 5 Reconstruction acceptance of the.9 NA6 spec 9. Tm (58 GeV field) magnetic field setting. production angle (mrad) note that the neutrino experiments themselves, partic 5 provide additional constraints on the flux simulations mation on primary interactions Below we present brief comments on how improv production momentum (GeV/c) and upcoming Fermilab experiments production a production angle (mrad)

25 25 LBNE Flux in Good Coverage Bins 6 Flux NuMu at Flux LBNE Far Detector Total numu flux Fraction of NuMu Flux Neutrino Energy (GeV) covered by current NA6 covered by NA6 with ftrack For red and green, the secondary Pi, K, or p, must be in a Current covered NA6 bin has good coverage of charged π,k that 5 contribute to LBNE flux (red line). With additional forward tracking could be improved (green line). (The remainder is from n, K, and Λ. Some of this should be possible to measure too.)

26 26 Neutron Measurements? A new projectile spectator detector (an HCAL) was commissioned for NA6 in 23 Could potentially use this to make direct measurements of forward n production

27 27 Summary T2K has benefited greatly from a suite of thin and thick target measurements from NA6 Increased statistics and data analysis improvements from NA6 will improve this over the next 2 years Thin target data at 6-2 GeV/c could similarly benefit LBNE. Possible opportunity to start to take this data at NA6 in 25